George Lansbury was, according to the historian AJP Taylor, one of the most well-loved figures in modern politics, yet is largely forgotten now. But as well as being leader of the Labour party from 1932 to 1935, he was a pacifist, anti-imperialist, supporter of votes for women and a republican before these ideas gained greater currency. He was also jailed twice on matters of principle, edited the Daily Herald, the workers' newspaper, and founded a dynasty that included Hollywood producers and the actor Angela (Murder She Wrote) Lansbury.

Lansbury's achievements are being celebrated this week during the 150th anniversary of his birth.

Tonight, the House of Lords will host a discussion on his legacy with former Labour deputy leader Roy Hattersley, Lib Dem peer Shirley Williams and Lansbury's biographer, Professor John Shepherd. On Friday evening, former Labour MP Tony Benn and professor Mary Davis, biographer of the suffragette Sylvia Pankhurst, will join a public debate at Bromley Hall in Lansbury's old constituency of Bow in east London to ask if Taylor's epithet still holds true.

Organiser Nigel Whiskin, Lansbury's great-grandson, says: "Lansbury stood up for the underdog. His views were right for the days he lived, although I wouldn't share all of them. But Labour pioneers were so steadfast and inspiring when you consider what they achieved."

In 1921, as mayor of Poplar, one of the poorest boroughs in the country, Lansbury and all 29 other councillors were jailed for refusing to hand over what they saw as an unfair tax. Instead, they used money collected in rates to build homes with better sanitation and to introduce equal pay for male and female council workers on a minimum wage far in excess of the market rate.

Benn, who met Lansbury, describes him as "a great inspiration to the early Labour party", but he points out that he is now a forgotten figure, as he died in 1940 before Labour got into power.

"He was also a man of high principle and paid for it," says Benn. "He was jailed twice; once for sedition [for supporting the suffragettes]. The second time, when he led the council in Poplar, they actually held council meetings in Brixton prison."

As Labour leader in the early 1930s, Lansbury's pacifism in the face of German and Italian aggression proved fatal for his political career. He resigned after the 1935 party conference, where Ernest Bevin accused him of "hawking his conscience around".

There are still a few signs of Lansbury's achievements in the East End, including a mural celebrating the rates rebellion and the architecturally acclaimed Lansbury Estate, built amid Festival of Britain optimism. And on the site of his former home in Bow Road stands a tiny stone memorial that reads: "A great servant to the people."